Species Diversity Analysis of the Aquatic Insect in Paddy Soil

Abstract

The aquatic insect collected at six areas (each 2 for mountain area, plain field, and urban area) from 2009 to 2011 were classified to analyze the distribution and diversity of species. Frequency (number of aquatic insect: N), number of species (S), similarity index (C), richness index (R1, R2), variety index (V1, V2), evenness index (E1, E2, E3, E4, E5), and dominance index (D1) were investigated. Total N and S were 143 and 84, respectively. C matrix of 153 combinations was constructed with the average of 0.542. The average C of 3 years (0.659) was 9.9% P , more higher than the average C of 6 areas (0.560). The average values of the index of 18 plots were 2.28, 0.17, 1.24, 1.08, 0.07, 0.06, 0.01, 0.87, 0.31, 0.93 for R1, R2, V1, V2, E1, E2, E3, E4, E5, D1, respectively. The order in the coefficient of variation (CV) of the indicator for 18 plots was N (70.0%) > E3 (54.9%) > E1 (49.6%) > R2 (40.5%) > S (35.3%) > R1 (33.7%) > E2 (28.4%) > E5 (15.9%) > V1 (11.1%) > E4 (6.3%) > V2 (5.1%) > D1 (4.8%). The correlation matrix with 66 combinations between the indexes was constructed with statistical significance for 33 combinations. However, R1, V1, E2 and D1 were the proper indexes to represent species diversity of aquatic insect based on the correlation matrix and the theory of statistical independence. The richness index was highest in mountain, variety index in urban area, and evenness index in plain field. However, the dominance index was lowest in urban area.